fix standardize QoS configuration value in hystrix sample (#1236)

diff --git a/4-governance/dubbo-samples-spring-hystrix/src/main/resources/spring/hystrix-dubbo-provider.properties b/4-governance/dubbo-samples-spring-hystrix/src/main/resources/spring/hystrix-dubbo-provider.properties
index e738ed4..5548ca8 100644
--- a/4-governance/dubbo-samples-spring-hystrix/src/main/resources/spring/hystrix-dubbo-provider.properties
+++ b/4-governance/dubbo-samples-spring-hystrix/src/main/resources/spring/hystrix-dubbo-provider.properties
@@ -17,7 +17,7 @@
 #
 #
 dubbo.application.name=hystrix-annotation-provider
-dubbo.application.qos.enable=disable
+dubbo.application.qos.enable=false
 dubbo.registry.address=zookeeper://${zookeeper.address:127.0.0.1}:2181
 dubbo.protocol.name=dubbo
 dubbo.protocol.port=20885